Researchers found that in the weeks after the San Bernardino and Sandy Hook shootings, many Californians rushed to buy handguns.

A new study published Monday found that in the wake of two high-profile mass shootings, handgun sales spiked in California.

Sales in the state rose by 53 percent during the six weeks after the 2012 shooting at Sandy Hook Elementary School in Newtown, Connecticut.

After a 2015 mass shooting in San Bernardino, sales rose by 35 percent in most of California. But they nearly doubled within San Bernardino County, growing by 85 percent.

"It's quite a remarkable response," said Stanford University professor David Studdert, who led the study.

Studdert said this phenomenon has been widely recognized for awhile, but he and his colleagues wanted a more detailed understanding of these spikes and who was driving them.

California, with its relatively strict gun laws, makes sales figures more readily available than other states. The researchers combed through data retained by the California Department of Justice and found that after mass shootings, certain demographic groups become more likely to buy guns.

"Women proportionally increase to a larger extent," Studdert said. "We see a larger response among first gun buyers. And we see a larger response among whites and Hispanics."

The researchers do not know why some people choose to buy guns when mass shootings are in the headlines. But they note that surveys indicate self-protection is a leading concern among gun owners generally.

"It is difficult to get firearm research funded," said Studdert. "But in this case we were able to do it on our own."

These sales spikes account for less than 10 percent of California's total gun sales in a given year. But Studdert said they are significant enough to have potential implications for public health.

"When we see shocks that stimulate gun purchasing like this, it causes concern that there may be a feedback loop," Studdert said. "With additional gun purchases come additional concerns about security, and that prompts more people to buy weapons, and so on."